Shear guard



April 22, 1958 H. w. ROCKOFF ETAL SHEAR GUARD Filed May 7, 1956 United States Patent SHEAR GUARD Howard W. Rockoif and Steve R. Smith, Wisconsin Dells, Wis., assignors to Guard, Inc., Wisconsin Deils, Win, a corporation of Wisconsin Application May 7, 1956, Serial No. 583,318

Claims. (Cl. 74-616) machine will be intermittent. This continuously running machine with its heavy cutting blade and flywheel action is dangerous if there is no guard around the cutting blade when not in use as someone coming too close to the machine may be injured by the oscillating heavy blade.

Accordingly, it is an object of the present invention to provide a guard for a cutting machine when it is running but not in use.

Another object of the present invention is to provide a guard for a cutting machine that is selectively operable to be maintained in the open position when the machine is in use.

Other-objects will be apparent from the following description when read in connection with the drawings, in which:

Fig. 1 is an isometric view partly cut away and partly schematic showing the guard on the cutting machine in closed position;

Fig. 2 is a view similar to Fig. 1 showing the guard in the open position;

Fig. 3 is an isometric view of another embodiment of the invention; and

Fig. 4 is an isometric view showing an enlargement of part of the linkage shown in Fig. 3.

Referring to the drawing by characters of reference Fig. 1 illustrates the guard positioned in closed position on the cutting machine 11. It will be seen that on cutting machine 11 only the oscillating cutting blade 12 and the complementary cutting block 13 are shown, and it will be understood that a conventional power mechanism can 4:

be used to operate oscillating blade 12. Hardened portions 14 are visible as the cutting edges of blade 12 and block 13.

Guard 10 comprises a plate like guard member 16 adapted to be positioned in a vertical plane atop cutting block 13. As shown in Fig. 1 guard member 16 is in a closed position wherein the bottom edge thereof is in abutting relation with cutting block 13 thereby preventing passage of any material between the cutting edges of blade 12 and block 13. A mounting 17 connects guard member 16 to a rotatable sleeve 18. Mounting 17 can be connected at one end substantially at the midsection of guard member 16 and at the other end to sleeve 18 by welding, Mounting 17 can be constructed with plates welded perpendicularly to each other as shown in Fig. l. Sleeve 18 is pivotally mounted on stationary shaft 19 which is attached to cutting block 13 so that guard mem The machine generally includes a heavy cutting 2,831,371 Patented Apr. 22, 1958 is positioned rearwardly so that guard member 16 is thereby weighted so as to rotate clockwise as viewed in Fig.1 and assume the angular open position shown in Fig. 2 if no other forces are acting on guard member 16.

Attached at pivot 24 is a foot lever 26 which includes a foot pedal 27 at the front end of cutting machine 11. At the rear end of lever 26 is formed a slot 28 in which is slidably mounted an upwardly extending rod 29. Hollow tube 31 is positioned vertically and mounted on block 13 by a bracket 30. Rigid rod 29 extends upwardly. into tube 31 and is attached to the bottom of a cup 32 which is slidably mounted to be aligned vertically in tube 29.

A weighted element 33 is detachably seated in cup 32 and has a flexible connector such as a rope 34 connectedtherewith at one end and passing upwardly over pulleys 36 and 37 and then passing downwardly to be connected at its other end to the rearward top edge at tie point 35 of cutting blade 16 adjacent weight 22. Element 33 has a suflicient weight that more than counterbalances weight 22.

During the operating condition of cutting machine 11 when blade 12 is oscillating but the machine is not being used, guard member 16 will assume the closed position shown in Fig. 1. This closed position is assumed as the weight of element 33 being greater than weight 22 pulls down on rope 34 and transmits a lifting force to weight 22 and the rearward portion of guard member 16. The forward bottom turned edge portion 38 of guard member 16 is thereupon maintained in closed contact with the top of block 13 and prevents anything from passing between the cutting edges 14.

When it is desired to use machine 11 for cutting material such as heavy metal, foot pedal 27 is depressed thereby raising rod 29, cup 32 and weighted element 33. The tension is thereupon removed from rope 34 and the lifting force on tie point 35 no longer exists so weight 22 will thereupon cause guardmember 16 to rotate clockwise on shaft 19 and assume the open position shown in Fig. 2 wherein it is seen that the bottom edge of guard member 16 forms an acute angle with cutting block 13. As long as foot pedal 27 is depressed, guard member 16 will remain open and material can be placed on cuttting block 13 for shearing. As seen in Fig. 2 blade 12 is shown in the raised position ready to rotate downwardly and shear any material placed on block 13.

It will be noticed that a resilient stop cushion 41 is mounted on the rear part of block 13 to determine the limit position and cushion the shock of the opening of guard member 16. As mentioned before element 33 is detachably seated in cup 32, which will prevent operational shocks being transmitted to the operators foot,

Fig. 3 illustrates another embodiment of the present invention, and the same numerals have been used for corresponding parts shown in Figs. 1 and 2. It will 'benoticed that mounting 17 is fastened to the rearward portion of guard member 16 so that the forwardly weighted end of guard member 16 tends to rotate guard 19 counterclockwise and maintain the guard in closed position as shown in Fig. 3. part 51 is attached by bracket 52 to sleeve 18 so that when guard member 16 is in the closed position, weight sl will be suspended vertically downward from sleeve 18.,1If guard member 16 is rotated to the open position as shown in Fig. 1, weight 51 will rotate in diametrically opposed An element or weighted I .3 relation against the gravitational pull and will thereupon build up a kinetic force tending to return the guard 10 to the closed position when the force holding the guard in open position is removed.

' It will be noticed that foot lever 26 at its rearward end has an upwardly open crimped cup section 53 which receives a rod 54 that is mounted on pivot assembly 56. Accordingly, it is seen that depression of foot pedal 27 in Fig. 3 will cause the end of rod 54 positioned in cup section 53 to be raised, and the other end 57' of rod 542 will pivot downwardly about pivot bracket 56 which is rigidly fastened to support bracket 42 that is mounted on Cutting block 13. A flexible connection shown as rope 58 can be adjustably tied to any one of a plurality of holes in the rod end 57 and then passes over pulley 59 and extends horizontally to be tied to guard It). Pulley 59 is mounted on block 13 by a bracket assembly 61, and a further supporting bracket 62 is welded to mounting 17 to which rope 58 can be attached at tie point 63.

As mentioned before, depression of foot pedal 27 iv causes rod end 57 to move downwardly, thereupon pulling rope 58 downwardly so that bracket 62 is pulled rearwardly and guard 10 is rotated clockwise to the open position. Release of foot pedal 27 allows guard 10 to assume the closed position shown in Fig. 3 due to the tendency of weight 51 and the forward portion of guard member 16 to rotate counterclockwise about shaft 19.

An additional embodiment of a stop means which will cushion the end of the opening movement of guard 18 is shown in Fig. 3. The stop means 66 comprises a yoke member-67 attached at the lower part 43 of sleeve 13 to rotate therewith. A rod 68 is fastened to yoke 67, and a spring 69 is wound around rod 68. A bracket 71 is attached to block 13 and has its outer end formed with a slot 72 to slidably receive rod 68. At the rearward end of rod 68 and positioned rearwardly of slot 72 is a collar 73 which is adjustable to be selectively positioned along rod 68. Opening movement of guard 10 rotates sleeve 18 clockwise causing rod 63 to slide forward in slot 72. When collar 73 comes in contact with slot 72, opening movement of guard 19 ceases, and accordingly, it is seen that the position of collar 73 on rod 68 determines the maximum open position of guard 10. Spring 69 is fastened at one end to rotating yoke 67 by welding to a cup and nut assembly 44 fixed on rod 68 and at the other end to fixed bracket 71 by welding so that opening movement of guard 10 stretches spring 69 creating a dampening effect tending to cushion the shock of the opening movement.

It should be pointed out that although the particular embodiments shown are directed to a shearing machine, the subject invention is not to be limited thereto as the type of guard illustrated can be applied to any cutting machine.

' The particular embodiments of the invention illustrated 5? and described are to be considered illustrative only. The present invention includes such other modifications and equivalents as may readily occur to those skilled in the art, within the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. A guard for a cutting machine comprising a cutting block and a continually oscillating cutting blade associated therewith, a guard member pivotally mounted on said cutting block and adapted to oscillate in a plane parallel to the plane in which said cutting blade oscillates, said guard member having a weight component adapted to maintain the bottom edge thereof in abutting relation with said cutting block, the cutting surfaces of said cutting block and said cutting blade associated so that material to be cut cannot be inserted therebetw'een when said abuttingrelation exists between said cutting block and said guard member, selectively operable means connected with said guard member and adapted to overcome said weight component and pivot said guard member to open position, said bottom edge of said guard member 4 1 forming an acute angle with said cutting block when sai guard member is in open position. a a

2. A guard for a cutting machine comprising a cutting block and a continually oscillating cutting blade associated therewith, a guard member pivotally mounted on said cutting block and adapted to oscillate in a plane parallel to the plane in which said cutting blade oscillates, said guard member mounting attached rearwardly of the center of said guard member so that the greater weight of the forward end of said guard member tends to main tain the bottom edge thereof in abutting relation with said cutting block, the cutting surfaces of said cutting block and said cutting blade associated so that material to be cut cannot be inserted therebetween when said abutting relationship exists between said cutting block and said guard member, an element having a substantial weight attached to said guard member so as to be positioned below said pivot mounting, selectively operable means connected with said guard member and adapted to pivot said guard member to open position, said weighted element being pivotally rotated against the force of gravity and said bottom edge of said guard member forming an acute angle with said cutting block when said guard member is in open position.

3. A guard for a shearing machine comprising a shearing block and complementary continually oscillating shearing blade, a guard member having a mounting attached to the rearward part thereof, said mounting being pivotally connected on-one side of said shearing block so that said guard member oscillatesin a plane parallel to the plane in which said shearing blade oscillates, the part of said guard member forward of said mounting having a SLlifiCltBIlli weight component to normally maintain the bottom edge of said guard member in abutting relation with said shearing block, the shearing surfaces of said shear; ing blocs and said shearing blade associated so that material to be sheared cannot be inserted therebetween when said abutting relationship exists between said shearing block and said guard member, an element having a substantial weight attached to said guard member so as to be positioned below said pivot mounting, a linkage assembly comprising a lever selectively operable to effect rotation of said guard member to open position, said weighted element being suspended vertically from said mounting when said guard member is in closed position and adapted to be pivotally rotated against the force of gravity and said bottom edge of said guard member forming an acute angle with said shearing block when said guard member is in open position, and stop means comprising a spring slidably mounted on a rod having one end of said spring and rod fixed to said rotatable mounting and the other end fixed to said shearing block, said rod having a collar adjustably fixed thereon, said collar adapted for limited sliding movement when said mounting rotates to determine the maximum open position of said guard member.

4. A guard for a cutting machine comprising a cutting block and a continuously oscillating cutting blade associated therewith, a guard member pivotally mounted on said cutting block and adapted to oscillate in a plane parallel to the plane in which said cutting blade oscillates said guard member weighted at the rearward portion thereof to assume the open position'wherein the bottom edge of said guard member forms an acute angle with respect to said cutting block, an element having suflicient weight to more than counterbalance said weigh-ted rear ward portion of said guard member, said element connected with said rearward portion of said guard member to exert an upward force component on said rearward portion maintaining the bottom edge of said guard member in abutting relationship with said cutting block in closed position, the cutting surfaces of said cutting block and said cutting blade associated so that material to ,be cut cannot be inserted therebetween when said abutting relationship exists, and means selectively operable to position said element to remove said upward force component to place said guard member in open position.

5. A guard for a shearing machine comprising a shear ing block and a complementary continually oscillating shearing blade, a guard member pivotally mounted on said shearing block and adapted to oscillate in a plane parallel to the plane in which said shearing blade oscillates, said guard member having an adjustable weight attached to the rearward portion thereof to cause said guard member to assume the open position wherein the bottom edge of said guard member forms an acute angle with respect to said shearing block, a vertically positioned element having sufiicient weight to more than counterbalance said weighted rearward portion of said guard member, a tube having a cup member vertically slidably mounted therein and adapted to have said element detachably received therein, a foot lever having one end rigidly connected to said cup for vertical actuation thereof, flexible means connecting said element with said guard member to allow the greater weight of said element to counterbalance said adjustable weight and maintain said guard member in closed position wherein the bottom edge of said guard member is maintained in abutting relationship with said shearing block, the shearing surfaces of said shearing block and said shearing blade associated so that material to be sheared cannot be inserted therebetween when said abutting relationship exists,

said foot pedal adapted for pivotal movement to raise said cup and element to offset the counterbalance weight of said element and allow said adjustable weight to swing said guard member into open position, and stop means mounted on said shearing block to limit the maximum open position of said guard member.

References Cited in the file of this patent UNITED STATES PATENTS 

